This invention relates to a passenger side air bag module.
An air bag module typically comprises an air bag and an air bag inflator. When a severe crash is detected by a vehicle's crash detection system, the system may instruct the air bag module to deploy. If this event occurs, the air bag inflator rapidly discharges an inflation gas at a very high temperature into the air bag. The high temperature of the gas causes its rapid expansion, thereby inflating the air bag to form a cushion against vehicle impact for a vehicle occupant. Preferably, the air bag should deploy towards the vehicle occupant to maximize cushioning. However, challenges arise in the design of an air bag module for a passenger side air bag. Specifically, due to the shape of passenger side air bag inflators, inflation gas from the air bag inflator may discharge toward the side of the vehicle occupant. As a consequence, the air bag may deploy toward the side of the vehicle occupant rather than in the direction of the occupant.
Manufacturers have sought to overcome this design challenge by using a vent to redistribute the flow of inflation gas across the mouth of the air bag through guide structures, such as holes or vanes, located between the air bag inflator and the air bag. Vent holes are not very effective in redistributing air flow. Moreover, the vanes that manufacturers currently use extend between the air bag inflator and the air bag and are located outside of the air bag. Applicant has discovered that these vanes draw heat away from the inflation gas and consequently reduce its ability to expand the air bag.
A need therefore exists for an air bag module that redirects the flow of inflation gas towards the vehicle occupant without significant heat loss.